Apparatus and method for electrically killing plants

Abstract

An electrical apparatus to kill a plant or at least attenuate plant growth, the apparatus comprising: an power supply unit; an applicator unit comprising an applicator electrode; an return unit comprising an return electrode; electrical circuitry; the power supply unit arranged to apply electrical energy through a transmission circuit comprising the applicator electrode, and the return electrode, wherein said electrical circuitry implements a detection system to determine a condition of electrical arcing of the electrical energy from one or both of said electrodes, the electrical circuitry arranged to control the electrical energy through the transmission circuit to at least partially reduce the electrical arcing based on said determined condition of electrical arcing.

The invention claimed is: 
     
       1. An electrical apparatus to kill a plant or at least attenuate plant growth, the apparatus comprising:
 a power supply unit; 
 an applicator unit comprising an applicator electrode; 
 a return unit comprising a return electrode; 
 electrical circuitry; 
 the power supply unit arranged to apply electrical energy through a transmission circuit comprising the applicator electrode, and the return electrode, wherein said electrical circuitry implements a detection system to determine a condition of electrical arcing of the electrical energy from one or both of said electrodes, the electrical circuitry arranged to control the electrical energy through the transmission circuit to at least partially reduce the electrical arcing based on said determined condition of electrical arcing; and 
 wherein the electrical apparatus further comprises at least one of:
 a camera system to detect the electrical arcing; 
 a thermal sensor to detect the electrical arcing by heat generated therefrom; and 
 the detection system being arranged to determine the electrical arcing by determining electrical noise caused by the electrical arcing. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein said control of the electrical energy includes altering one or more of the following electrical quantities to at least partially attenuate electrical arcing: electrical potential over the said electrodes; and electrical current through said transmission circuit; and electrical power through said transmission circuit; the frequency of the electrical energy; phase between of the electrical current and voltage. 
     
     
       3. The apparatus of  claim 2 , wherein said electrical quantity is altered until the detection system determines that electrical arcing has stopped. 
     
     
       4. The apparatus of  claim 3 , wherein following determination that electrical arcing has stopped, the electrical circuitry is further configured to reapply unaltered electrical energy through the transmission circuit. 
     
     
       5. The apparatus of  claim 4 , wherein the unaltered electrical energy is reapplied instantaneously. 
     
     
       6. The apparatus of  claim 4 , wherein the unaltered electrical energy is reapplied progressively over a period of time. 
     
     
       7. The apparatus of  claim 6 , wherein the electrical circuitry is arranged to determine the condition of electrical arcing during the progressive reapplication and if electrical arcing determined then to control the electrical energy through the transmission circuit to at least partially reduce the electrical arcing based on said determined condition of electrical arcing. 
     
     
       8. The apparatus of  claim 2 , wherein the electrical circuitry is configured to execute the following machine executable steps following the determination of the condition of electrical arcing:
 Step A: wait a predetermined amount of time; 
 Step B: determine with the detection system if electrical arcing is still present; 
 Step C: if electrical arcing not present then reapply unaltered electrical energy, if the electrical arcing is still present then loop to step A. 
 
     
     
       9. The apparatus of  claim 2 , wherein said electrical quantity is altered for a predetermined amount of time after which unaltered electrical energy is reapplied. 
     
     
       10. The apparatus of  claim 1 , wherein said control of the electrical energy includes implementation of alternative applicator electrode and/or return electrode for transfer of said electrical energy. 
     
     
       11. The apparatus of  claim 1 , wherein said control of the electrical energy comprises implementation of electrical damping in the transmission circuit. 
     
     
       12. A method of treating a plant with electrical energy using the electrical apparatus of  claim 1 , the method comprising:
 applying electrical energy to the plant between the applicator electrode and the return electrode of the electrical apparatus; 
 determining electrical arcing proximal one of said electrodes; 
 controlling the electrical energy to reduce the electrical arcing. 
 
     
     
       13. An electrical apparatus to kill a plant or at least attenuate plant growth, the apparatus comprising:
 a power supply unit; 
 an applicator unit comprising an applicator electrode; 
 a return unit comprising a return electrode; 
 electrical circuitry; 
 the power supply unit arranged to apply electrical energy through a transmission circuit comprising the applicator electrode and the return electrode, wherein said electrical circuitry implements a detection system to determine a condition of electrical arcing of the electrical energy from one or both of said electrodes, the electrical circuitry arranged to control the electrical energy through the transmission circuit to at least partially reduce the electrical arcing based on said determined condition of electrical arcing, and wherein the detection system comprises circuitry to determine the condition of electrical arcing based on a change in a property of the electrical energy. 
 
     
     
       14. The apparatus of  claim 13 , wherein the property of the electrical energy comprises one or more of: a change in an electrical potential over said electrodes; a change in electrical current or power though the transmission circuit; a reduction of electrical resistance between said electrodes; a change in phase between the current and voltage of the electrical energy; electrical noise due to the electrical arcing; a first order time derivative of one of the aforesaid quantities, above/below a threshold. 
     
     
       15. A method of treating a plant with electrical energy using the electrical apparatus of  claim 13 , the method comprising:
 applying electrical energy to the plant between the applicator electrode and the return electrode of the electrical apparatus; 
 determining electrical arcing proximal one of said electrodes; 
 controlling the electrical energy to reduce the electrical arcing.